Optical connection between optical fibers and electro-optical elements generally is provided by cementing one end of the optical fiber to the electro-optical element by means of a transparent adhesive. Since maximum light transmission is desired between the fiber's optical source and the fiber's light detector, apparatus is generally employed to insure proper alignment and to promote minimum losses to the system. When an epoxy-type cement is employed to join the optical fiber to the electro-optical element some time is required to allow the epoxy to cure and become set. Particular care must be taken during the curing process to insure that the element and fiber do not move out of optical alignment.
Another problem with the method of connecting between electro-optical elements and optical fibers by cementing the fiber end to the electro-optical element is the extreme fragility imparted to the fiber because of the small dimensions and long lengths of fibers usually involved.
When light emitting diodes are employed as optical emitters in light communication systems, and are connected directly to optical communications fibers by means of a clear epoxy cement, there is a possibility that the epoxy material will react with the diode structure to result in premature diode failure. It is generally desired, therefore, to provide optical connection between the fiber and the electro-optical element without the use of an adhesive material.
The purpose of this invention, therefore, is to provide for good optical connection between electro-optical elements and optical fibers without cementing the fibers directly to the electro-optical elements.